Understand the different types of transport mechanisms: Active transport requires energy to move substances against their concentration gradient, while passive transport (including diffusion) does not require energy.
Recognize that simple diffusion involves the movement of small or nonpolar molecules directly through the lipid bilayer without the assistance of proteins.
Facilitated diffusion is a type of passive transport that uses transport proteins to move substances across the cell membrane along their concentration gradient.
Identify that glucose is a polar molecule and relatively large, which means it cannot pass through the cell membrane by simple diffusion.
Conclude that glucose enters the cell through facilitated diffusion, using specific transport proteins to help it cross the cell membrane without the expenditure of energy.